Method of drying air.



L. BLOCK.

METHOD OF DRYING AIR.

Arrmonlol nun nov. 1a, 1905.

Patented Nov. 10, 1908.

a inns-sum 1.

INVENTOR WITNESSES:

W Q Za/a L. BLOCK.

IETHOD OI DRYING AIR.

mom-1o! run I APP ov.1a, 1005. 903,353. Patented Nov. 10, 1908.

WIN/E8858: INYENTOR i he termed solution in the atmos here is warmed for admission to the furnace.

UNITED stir-Ar as PATENT OFFICE.

Les-lessees, or messages, sew YQRK.

METHOD OF DRYING no. 903,353. Specification of Lettera Patent. Patented Nov. 10, 1908.

. 7 Application filed November 18, 1905. Serial N- 287,915.

To all 'whom i't may concern: I densed and removedtlcan allow the air to 65 Be it known that I, LOUIS BLOCK, a citizen again expand and therebyto drive an ens ne of the "United States,-residing at Mamarowhich contributes to the power require to neck, in the county of VVestchesterand State effect the compression or to do other useful of New York, have invented certain new and work. In other words I-can cause the same useful 1m rovements in Methods of Drying low-tension cold air, after it has parted with .\ir. of w ich the following is a specificaits moisture in the form of water by ,trap- 1 lion. ping out, or of snow, by any suitable means I will describe the invention as applied to of extracting-such, to be presented in a heat removing the moisture from the air forced exchangerto the high tension hot air before up throu h the highl resisting mass of fuel, the action of the latter in the'expanding enore, and dime, in a b ast furnace, or a ainst gine, and thus secure the further lowering the strong pressure due to the has. of of the temperature of the high pressure air melted iron in a Bessemer converter. 1 will for the removal of moisture and also the use the brief term blast furnace to mean partial warmin of such low-pressure air beeither. The moisture thus held in what may fore its intro uction to the stove to be about the same per cubic foot for any given I have devis d mean f CM .in'g t t e temperature, whether the pressure be great n ent on 11 Several forms. he accomor small. Thusif the air at ordinary atmospanying diagrammatic drawin 's form a pheric pressure at ordinary temperature can p rt of this Specification. I wild Show and told l-l grains per cubic foot and it is taken describe first one of the most simple.

in with 10 grains, compressing such air to a Figure 1. is an outline view fpartly in vertension of five atmos ieres, gives it 50 grains lical section, showin some 0 the parts of per cubic foot, whie ,if cooled down to its the apparatus proper y connected, and Figs. original temperature-is 36 grains more than l and 2 Show a certain portion on a larger" it can hold and the sur lus can be deposited scale. Eachis an elevation partly in veriu the form of water. f still further cooled, tical section. Fig. 2 is a corresponding plan so that the capacity .for moisture is reduced, V ew h 'I g the Same h mp rt n dd thenstill more moisture will be liberated, the tions, constituting the apparatus complete.

water, in such case usually assuming the Similar letters of reference indicate like form of snow, It is highly advantageous to parts in all the figures where they appear. have but a small and uniform quantity of In Figs. 1 and 2 A is an air compressor moisture in the air for-the blast furnace. The of any suitable-type preferably that setforth importance of attai ing this end has been in an a plication'for-U. S. Patent made by long a preciated and many forms of appame, refi ed on the 3d of August, 1904, Serial ratus or these purposes-have been devised, Number 219,291, driven by a steam engine some of which are in use. My improvement D or other 'efiicient means. A is a pi e of -makes the treatment of the air highly eflisufiicient capacity conducting the air t erecient and considerably more economical from at high tension, say 60 pounds er than any before known to me. square inch, and at a high temperature ue I have discovered that it is practicable to to the compression. compress the air toa tension above that re- B is a moderate cooler or condenser; a uired for the blast furnace and to dispose strong casing provided with tubes. I flow of the heat of compression by cooling such ordinary river water or Well water if such compressed air by water at ordinary temcan be commanded, through the spaces be-v peratures, or better still by cold air after it tween, while the hot compressed air flows as deposited its moisture. Such treatment through the tubes, or I reverse these conditakes away the heat. of compression by transtions; the whole purpose being to' expose ferring it to that cooling medium which is this air to metal of suflicient area ke t at allowed to fiow away warm. After this nearthe tem erature of the coolin me ium, 1 treatmcnt'has cooled the air in its highlysay 35 to 90 ah., and thus to coo the comcompressed condition to an ordinary temper pressed air down to about that temperature.

ature and its surplus moisture has con con-y; Next referring to Fig. 1 alone,-B' is a pipe carrying away the air still under its if a valve becomes clogged by ice. In this cylinder it is caused by suit-ably actuated valves to act alternately on the opposite side of a piston not shown and through a piston rod D", to aid in driving the compressor A or to do other useful work. This motor enine does not require specific description, he admission-valve or valves should be worked in the same manner as the corresponding arts in a good steam engine so as to cut 0 the supply of air when only a third or some other fraction of the stroke has been performed and thus to obtain power from the expansion as 'well as from the admission of the air and utilize as far as may be all the power derivable from the expansion of the air from near the high tension,

say 60 lbs. per square inch bygage at which it left the compressor A too near the blast furnace tension. '1 will. use the term furnace tension to indicate the pressure say 20 lbs. above atmosphere at which the air blown into the blast furnace through the ordinary twyers after being heated by the ordinary stove. is able to overcome the resistance and risethrough any ordinary or ex traordinary mass of material in the blast furnace.

D and D by valves D and D arranged to conduct the expanded air to snow boxes E and 1*, which latter may be of ordinary or suitable construction. The pressure is now down to that required to serve in the blast furnace, the furnace tension. The soft ice or snow, if any is -deposited, maybe alternately removed from the snow boxes, and the air pretty-thoroughly rid of its moisture may be conducted by any suitable passages or vessels as the ipes E E and F controlled b the valves F connecting tothe stove C1 after being there heated flows through the 'twyers' into the blast furnace H; Its dryness makes it economical. enablesthe iron master to deliver pig iron of more uniform quality and with lessthan the "usual labor. The preparation of the air is attainedby my method with little machinery or care. The invention is useful in this slmple form.-

Fig. 2 shows the invention full V developed. Here the com ressing is e ected at two Stages. Any esired proportion, preferably more than half of the com ressmg is effected in the first-compressor and much heat'is here develo d. This is by a heat exchanger tra erred, the moderately high tension hot air coming from A and flowing onward to M giving its heat, to l are divergent pipes cont-rolled and Its uniformity bya the cold air at furnace tension coming flowcircuitous route, from the motor D an ing onward to the stoves.

When atmospheric. air in a condition near saturation is compressed to about three atmospheres in the first compressor A its cooling while so compressed to about 60 F. in

the heat exchanger 0 will cause much mois ture to be set free in the high pressure space in the heat exchanger. Such moisture precipitated from the freely inducted and partially compressed air will be discharged through the trap C The moderately high tension air after thus leaving part, of its heat and part of its water in the heat exchanger C flows through the pipe C to the second compressor M, shown as operated by a steam engine M. Here it is compressed to the final high tensionassum'ed to be five atmospheres absolute, its temperature being again raised by the compression and is led by the pipe M to a condenser B in which it is cooled by as cold water as can beobtained flowing through a liberal quantity of tubes while the air circulates through the spaces between and is cooled nearly to the temmay be. More water will be liberated at this stage and will be collected and allowed to escape through the second trap B The air at its intensely high tension, and normal temperature, say F and holding only the quantity of moisture'due to such temperature, about 14 grains. per cubic foot of the compressed air which is equivalent to about two and four-fifths grains per cubic foot of air under atmospheric pressure, now fiows through the pipeB to the motor D in which it is expanded and actuating a piston not shown, exerts power through the piston rod D to actuate the first compressor A or to do other useful work.

The compressed air being allowed to expand in working through the cylinder D is lowered in pressure as 111 the form first described, tonear that of the blast furnace, the difl'erence being only that required to overcome the slight resistance in'movin freely through the several chambers. and passages interposed. This develops a -lowering of temperature which may go far below the freezing point.- The snow formed, if any, will accumulate in snow boxes E F and by properly operating by hand or by machine, can as in the other form be all removed. The cold airat near thefu'rnace tension, now flows t-hrou h the pipe E to the first heat exchanger 5, where as before referred to it abstractsthe heat-from freshly inductedhalf tension air and performs two useful functions, first,the warming of itself warming it on its introduction to the stoves G and thus to the blast furnace H, and second,the coolingof the half-tension hot I perature of the cooling water whatever that v to require the expenditure of less heat in through the second tra air just being received. This air deposits its moisture 1n the form of water wlnch as it accumulates in the bogom is discharged The hi h tension air holding only the moisture due to its fairly well booled condition, is now led to the motor through the pipe 1}. There is no objection to warming it agaln at this stage, oh the contrary there is a marked advantage in doing so. There is a large amount of warm water available for such use.

J "is a casing loosely inc-losing the pipe 13' through which the air at full tension is flowing to the motor. The water which has served to cool it in the condenser B and has in doing so become warm, is now delivered by the pipe B into one end of this casing J and after restoring much of its heat to the air in the inclosed pipe B is discharged and allowed to flow away through the pipe J. The warmth thus given to the high tension air in the pipe B is of advantage by increasing the effect of its expansion in the motor and also by reducing the risk of developing ex- .cess of cold in the motor.

In order to have the outfiowing water of a temperature hi her than' that of the outflowing air, it 511 ices to arrange the heat exchanger in the known way for causing the temperature of the outflowing water to approximate that of the inflowing air and conversely.

hlodifications may be made without departing from the principle or. sacrificing the advantages of the invention.

The connections of the pipes to the several other members may be varied, and should be in case the direction of the air currents require it. I can inject cold water with suitable provisions for afterward separating the 'ater from the cooled air: Fig. 1 shows such arrangement. This figl'ire shows a single spray nozzle Q in a capacious vessel R. There is a trap I which allows the discharge of the water without allowing the air to escape. K is a vessel analogous to a steam separator in which any entrained water is arrested and returned through the pipe K to a point below the water line in.

the vessel R. Fig. 2 shows corresponding provisions with three or .more spray nozzles. The number of nozzles and pipes may be varied indefinitely. In this figure there are special provisions for separating the water, including a perforated platform above the level. of the water and a series of pipes It leading the water down therefrom, below the surface of the water below. By this means the water is discharged without liability of being blown out even if there is a very strong current of the air. I can use the power of the motor for other purposes than aiding in the compression. 1 can use other ordinary or suitable means for separating and removing the soft-ice or snow formed by the expansion.- I describe the snow boxes as simple means which. may serve. The snow boxes may be much larger than shown.

The invention may be operated successfully and give air which is equally uniform.

.in its hygrometric condition and is fairly dry, by so proportioning the parts that the temperature will not, in the coolest part of the circuit, the passage from the motor to the heat exchange, be but little if at all. below the freezing point. In such case the snow boxes or other provision for collecting and removing the moisture in a solid or semi-solid form may be omitted.

I claim as my invention 1 In the treatment of air for blast furnaces, the process consisting in compressing the air to a tension higher than is required to force it through the furnace, cooling the so compressed air while it is under such higher tension, expanding the air to a lower but still superatmospheric tension, removing from thc air its water of condensation while the air is at a pressure and tem1.)erature whereat saturated air has, such 'low content of moisture as is desirable in the air supply of a blast furnace, and supplying under appropriate pressure to theblast furnace air having the so obtained low moisture content, said air being maintained under superatmospheric pressure after its said compression and cooling .untilit is supplied to the blast furnace, substantially as described.

2. In the treatment of airfor blast furnaces, the process consisting in compressing the-air to a tension higher than is required to force it through the furnace, cooling the so compressed air while it is under such higher tension by means of water of 35 to 90 degrees Fahrenheit expanding the air to' a lower but still superatmospheric tension, removing from the air its water of-condensation while the air is at a pressure and temperature whereat saturated air has such low content of moisture as is desirable in the air supply of a blast furnace, and supplying under appropriate pressure to the blast furnace air having the so. obtained low moisturecontent,- said air being maintained under superatmospheric pressure after its said compression and coolmg until it is supplied to the blast furnace, substantially as described.

3. In the treatment of air for blast furnaces, the process consisting in compressing the air to a tension higher than is required to force it through the furnace. cooling the so compresed air while'it is under such higher tension, expanding the air to a lower but still superatmospheric tension, causing it in such' expansion to perform useful work, removing from the air its water of condensation while the air is at. a pressure and temperature whereat saturated air has such lowcontent of moisture as is desirable in the air supply of' a blast-furnace, and supplying under appropriate pressure to the blast furnace an having the so obtained low moisture content, said air being maintained un-' der superatmos heric pressure after its said compression an cooling until it is supplied to the blast furnace, substantially as described.

4. In the treatment of air? for'blast fur:

1113065, the process consisting in compressing theair to a tension higher than is required to force it through the furnace, cooling the so compressed air while it is under such highertension, expanding the air to a lower but still superatmospheric tension, removing from the air its water of condensation while. the" air is at a pressure and temperature Whereat saturated air has such low content of moisture as is desirable in the air supply of a blast furnace, heating air of the so obtained low moisture content by causing it to 1 cool compressed air on its way to further treatment, and supplying underappropriate pressure such so heated air to the blast fur-. nace, said air being maintained under superatmospheric pressure after its said compression and cooling until it is supplied to the blast furnace, substantially as described.

In the treatment of air for blast furnaces, the process consisting in compressing the air to a tension higher than,is required to force it through the furnace, cooling the so compresed air while it is under such higher tension by means of an independent body of cooling medium, expanding the air to a lower but still superatmospheric tension, removing from the air its Water of condensation While the air is at" a'pressure and temperature Whereat saturated air has such low content of .moisture as is desirable in the air supply of ablastfurnace, heating air of the so obtained low moisture content by causing it conductively to cool compressed air on the way to be further cooled by said independent bodyof cooling medium, and supplying under appropriate pressure such so heated air to theblast furnace,

said airlbeing 'maintained under superat- -n 1osphe1 ic pressure after its said compres: slon and cooling until it is supplied to the blast furnace, substantially as described.

(3. Inthe treatment of air for blast furnaces, the process consisting in compressing the airto a tension higher than is required to force it through the furnace, cooling the so.- compressed air while it is under such higher tension, heating the so compressed and'cooled air, expanding the so heated airto a lower but still superatmospheric tension, causing it in such expansion to perform useful work, removing from the air its water of condensation while the air is at a pressure and temneraturewhereat saturated air has such low content of moisture as is desirable in the air supply of a blast fur nace, and supplying under appropriate pressure to the blast furnace air having the so obtained low moisture content, said air being maintained under superatmospheric pressure after its said compression andcooling until it is supplied to the blast furnace,

substantially as described.

7. The method of treating air for use blast furnaces which consists in subjecting such air to a cooling operation, effecting an lnterchange of temperatures between the air before and after sub ect'Ion to said cooling operation, heating the air that has beenv cooled and subjected to the interchanging operation, and passing it into the furnace.

8. The method of treating air for use in blast furnaces which consists ill-subjecting it to a cooling operation, then subjecting it toa further cooling operation, utilizing the temperature of such air at an earlier stage for raising the temperature of the air at a later stage, subjecting the-air thus treated to a heating, operation, and discharg1ng1t into the blast furnace.

Signedat the city of New York in the county of New York and State of New York this 16th'day of November A. D. 1905.

f LOUIS BLOCK.

Witnesses: v

JLOUIS F. BRAUN,

E. RASMUSSEN. 

